Effects of 12-Week Sorghum Consumption on Visceral Fat Area and Metabolic Parameters in Japanese Adults: An Exploratory Single-Arm Trial.

Background: Visceral fat accumulation is strongly associated with metabolic disorders, particularly in Japanese adults who accumulate visceral fat even at lower body mass index levels. Sorghum is a whole grain rich in resistant starch and polyphenols, which may influence visceral fat area (VFA). This exploratory study aimed to investigate the effects of 12-week sorghum consumption on VFA and metabolic parameters in Japanese adults with visceral fat accumulation. Methods: This single-arm intervention trial included adults aged 20-60 years with VFA ≥ 100 cm2 and no ongoing medical treatment. Participants consumed cooked sorghum (80 g/day, dry weight) for 12 weeks. Anthropometric variables, VFA, blood pressure, and blood biomarkers were assessed before and after the intervention. Dietary intake was evaluated using a three-day food record. Pre- and post-intervention values were compared using paired t-tests. Results: Nine participants completed the study. VFA significantly decreased after 12 weeks of sorghum consumption (p = 0.02). Alanine aminotransferase (ALT) levels showed a non-significant reduction, while other metabolic and hepatic biomarkers remained stable. No adverse changes were observed in dietary intake or physical activity. Eight of nine participants exhibited reductions in VFA. Conclusions: Daily sorghum consumption may contribute to reductions in VFA and improvements in liver-related biomarkers in Japanese adults with visceral fat accumulation. These findings provide preliminary evidence that partially replacing major carbohydrate sources with sorghum may support visceral fat management. Further confirmation in randomized controlled trials is warranted.